A battery is a device that converts chemical energy directly to electrical energy. In some applications, multiple battery cells, such as lithium battery cells, are assembled together to form a battery cell assembly so as to provide sufficient power for various applications. In order to assemble a plurality of battery cells, the cells are arranged in a stack along with generally planar frames. Portions of the battery cells are sandwiched between the battery frames. Tie rods can be used to hold the stack of battery cells together under slight compression. Each tie rod can extend through a passage collectively formed by aligned holes in the frames. Each tie rod can be fixed in place by, for example, a threaded nut, at each end of the tie rod.
However, this type of assembly does not provide sufficient stability and rigidity to the stack. For example, while the tie rods may fix the frames relative to each other in one direction (in the axial direction of the tie rod), they may move relative to one another in one or more directions transverse to the axial direction of the tie rod. This lack of stability and rigidity can preclude the suitability of this type of assembly to stacks having a large number of cells. Moreover, this type of assembly does not sufficiently isolate the tie rods from the battery cells. Indeed, in some instances, it may be possible for the tie rods and the battery cells to come into contact with each other, such as when the battery cells are oversized or not properly aligned in the stack. In such cases, the battery cell and the tie rod may contact each other in the spaces between adjacent frame members where portions of the battery cell are sandwiched. Consequently, a short can develop, which can adversely affect battery performance, shorten the battery life span and endanger people who may handle the battery.
Therefore, there is a need for a system that can minimize such concerns.